The embodiment relates to a battery charging apparatus. In particular, the embodiment relates to a battery charging apparatus capable of representing the maximum power efficiency and a battery charging method using the same.
Eco-friendly vehicles refer to vehicles using batteries and electric motors instead of oil fuel and engines. Although the electric vehicles have been first manufactured in 1873, the electric vehicles have not been put to the practical use due to the technical limitations such as the heavy weight and the charging time of the battery.
The eco-friendly vehicle has employed a secondary cell (battery) that is chargeable as an energy source. In general, the electric vehicle or the fuel cell vehicle actuates a motor by using battery power in driving, and charges the battery in stopping.
In this case, in order to charge the battery, a charger is provided in a vehicle. Recently, in order to reduce the charging time of the battery, the maximum output power of the charger has been increased
FIG. 1 is a block diagram showing an electric vehicle according to the related art.
Referring to FIG. 1, the electric vehicle includes a charging plug 10, a charging unit 20, and a battery 30.
Regarding the charging operation of the electric vehicle having the above operation, if the charging plug 10 is inserted into an AC power supply (for example, a stand provided in a charging station, or a power socket provided in a home or a building), the charging plug 10 receives AC power supplied from the AC power supply.
The charging unit 20 serves as a power conversion device provided in the electric vehicle, and converts the AC power into DC power if the AC power is received through the AC charging plug 10.
The battery 30 includes at least one battery cell to store the DC power supplied through the charging unit 20.
The electric vehicle having the above structure supplies the DC power to the battery 30 by converting the input AC power into the DC power when charging the battery 30.
In this case, recently, in order to reduce the charging time of the battery, the maximum output power of the charging unit has been increased. Therefore, the charging power according to the maximum output power is supplied to the battery, so that the charging time can be reduced.
However, there is a limitation when increasing the maximum output power of the charging unit, and a lot of time is spent in charging the battery by exclusively actuating only one charging unit.
In addition, the charging unit represents efficiencies varying depending on charging powers (voltages or currents) to be supplied to the battery 30. In this case, if the charging power to be supplied to the battery 30 is set to power representing a lower efficiency, power loss may be caused in a load region, so that a great amount of heat may be emitted and the delay may be caused in the charging of the battery.